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    Subject[PATCH] fix PHY polling system blocking
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    This patch fix the PHY poller, which can block the whole system. On a
    Freescale PPC 834x this result in a delay of 450 us due the slow
    communication with the PHY chip.

    For PHY chips without interrupts, the status of the ethernet will be
    polled every 2 sec. The poll function will read some register of the MII
    PHY. The time between the sending the MII_READ_COMMAND and receiving the
    result is more the 100 us on a PPC 834x.

    The patch modifies the poller a lit bit. Only a link status state change
    will result in a successive detection of the connection type. The poll
    cycle on the other hand will be increased to every seconds.

    Together this patch will prevent a blocking of nearly 400 us every two
    seconds of the whole system on a PPC 834x.

    The patch is against kernel 2.6.33. Please merge it.

    Signed-off-by: Stefani Seibold <stefani@seibold.net>
    ---
    phy.c | 5 ++---
    phy_device.c | 12 +++++++++---
    2 files changed, 11 insertions(+), 6 deletions(-)

    diff -u -N -r -p linux-2.6.33.orig/drivers/net/phy/phy.c linux-2.6.33/drivers/net//phy/phy.c
    --- linux-2.6.33.orig/drivers/net/phy/phy.c 2010-02-24 19:52:17.000000000 +0100
    +++ linux-2.6.33/drivers/net//phy/phy.c 2010-02-28 22:53:14.725464101 +0100
    @@ -871,9 +871,8 @@ void phy_state_machine(struct work_struc
    case PHY_RUNNING:
    /* Only register a CHANGE if we are
    * polling */
    - if (PHY_POLL == phydev->irq)
    - phydev->state = PHY_CHANGELINK;
    - break;
    + if (PHY_POLL != phydev->irq)
    + break;
    case PHY_CHANGELINK:
    err = phy_read_status(phydev);

    diff -u -N -r -p linux-2.6.33.orig/drivers/net/phy/phy_device.c linux-2.6.33/drivers/net//phy/phy_device.c
    --- linux-2.6.33.orig/drivers/net/phy/phy_device.c 2010-02-24 19:52:17.000000000 +0100
    +++ linux-2.6.33/drivers/net//phy/phy_device.c 2010-02-28 22:53:14.726464145 +0100
    @@ -161,7 +161,7 @@ struct phy_device* phy_device_create(str
    dev->speed = 0;
    dev->duplex = -1;
    dev->pause = dev->asym_pause = 0;
    - dev->link = 1;
    + dev->link = 0;
    dev->interface = PHY_INTERFACE_MODE_GMII;

    dev->autoneg = AUTONEG_ENABLE;
    @@ -694,10 +694,16 @@ int genphy_update_link(struct phy_device
    if (status < 0)
    return status;

    - if ((status & BMSR_LSTATUS) == 0)
    + if ((status & BMSR_LSTATUS) == 0) {
    + if (phydev->link==0)
    + return 1;
    phydev->link = 0;
    - else
    + }
    + else {
    + if (phydev->link==1)
    + return 1;
    phydev->link = 1;
    + }

    return 0;
    }




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